1. Field of the Invention
The present invention relates to a heat-insulating (adiabatic) cooking container which is ideal for use in cooking, wherein partially-cooked food or the like is thermally insulated with the finished cuisine being prepared thereafter, and, in particular, in which the opening-closing operation of the lid is easily accomplished.
2. Relevant Art
In general, heat cooking methods for cooking food are conducted using electric heating, direct heating, or the like. However, according to such cooking methods, problems exist in that breakdown of the food, as well as scorching and sticking are easily generated by excessive heat, while a large amount of heat energy is also consumed in the aforementioned process. As a cooking method capable of solving the aforementioned problems, a cooking method is known in which a finished cuisine is prepared by means of dipping the desired raw vegetables, grains, cereals, or the like, into boiling water or stock which has been brought to a boil, and then thermally insulating the partially-prepared food in its heated state for a long period of time.
A known heat-insulating cooking container which is ideal for use in this cooking method is shown in FIGS. 13 and 14.
The heat-insulating cooking container shown in FIG. 13 comprises an outer container 1 possessing heat-insulating properties, inner container 2, and lid member 3 possessing heat insulating properties for closing the mouth opening of the aforementioned outer container 1. Outer container 1 comprises a double-walled structure formed from an outer bottle and an inner bottle in a manner such that a vacuum insulating layer is formed between these inner and outer bottles.
On the peripheral portion of the aforementioned lid member 3, a convex member 5 is provided which protrudes toward the exterior and comprises rib walls 4 and 4 on each side therein. A hinge axis 6 is installed horizontally in between these rib walls 4 and 4.
In addition, a ring-shaped shoulder member 7 is installed on a peripheral mouth portion of outer container 1. A hinge-receiving member 8 engaging with the aforementioned hinge axis 6 and connecting in a rotatable manner to the aforementioned lid 3 is integrally formed in shoulder member 7. This hinge-receiving member 8 comprises upper face 8a possessing dimensions fitting in between rib walls 4 and 4 of the aforementioned lid 3. A tongue-sheet 8b is provided protruding directly upward from the outer edge of upper face 8a with the upper edge thereof curving inwards. This tongue-sheet 8b forms a translot which serves to stop hinge axis 6 installed in lid member 3. In addition, a stopper 8c is provided on the inner edge of upper face 8a for preventing separation of hinge axis 6 stopped (maintained) by means of the aforementioned translot from outer container 1. According to this conventional heat-insulating cooking container, a connecting portion connecting the lid member to the outer container is formed by means of engaging hinge-receiving member 8 of outer container 1 and hinge axis 6 of lid member 3.
Furthermore, in the heat-insulating cooking container shown in FIG. 14, in addition to the components provided in the heat-insulating cooking container of FIG. 13, a hook 32 is provided at the periphery of lid member 3 on the side opposite the aforementioned connecting portion. In addition, a locking mechanism is arranged facing this hook 32 which is formed by means of providing hook stopper 33 at the periphery of shoulder member 7.
The tip of the aforementioned hook 32 forms a fishhook-like shape curving inwards at an acute angle; on the outer surface of hook 32, grip 32a is provided for opening and closing hook 32. This hook 32 is also installed in a manner such that the base therein can be rotated using hinge 31 as the fulcrum.
In addition, hook stopper 33 which is formed on the outer container 1 side is constructed in a manner so as to engage with the curved portion of the fishhook-shaped tip of hook 32.
However, in the aforementioned conventional insulating cooking containers, only a structure in which hinge axis 6 of lid member 3 is maintained (stopped) in hinge-receiving member 8 of outer container 1 by means of a hinge portion is realized: thus, hinge axis 6 is able to move freely over upper face 8a of hinge-receiving member 8 between tongue-sheet 8b and stopper 8c, thereby generating rattling in the connecting portion.
In addition, in order to increase the heat-insulating properties of the container, lid member 3 forms a structure which depresses into the interior of outer container 1 as shown in FIGS. 13 and 14. However, due to the necessity of preventing convection from generating at the inner mouth base of outer container 1, when closing lid 3, it is not possible to provide a large space between the inner circumferential surface of outer container 1 and the peripheral surface of lid member 3 facing the aforementioned.
In this manner, when hinge axis 6 is displaced from a fixed position at which it is maintained, at the time of opening/closing lid member 3, this lid member 3 comes into contact with inner container 2 or outer container 1, and hence smooth opening/closing operations are not possible.
In addition, according to the heat-insulating cooking container in which a locking mechanism is provided as shown in FIG. 14, when locking lid member 3, the curved fishhook portion of hook 32 pushes into hook stopper 33; while when releasing this locking, grip 32a provided in hook 32 is lifted upwards toward the exterior, thereby separating hook 32 from hook stopper 33. Furthermore, when opening lid member 3, since the locking must be released before lifting lid member 3, it is necessary to conduct a two-stage operation. Consequently, this type of locking mechanism poses some troublesome operations.
Moreover, with regard to this type of locking mechanism, in order to reduce the leakage of heat from the space between lid member 3 and outer container 1 as much as possible, it is undesirable to provide excessive slack within the arrangement of hook 32 and hook stopper 33. As a result, when eccentricity or distortion is generated in the mouth portion of outer container 1, the locking of hook 32 and hook stopper 33 cannot always be reliably conducted, thereby leading to fears of insufficient heat-insulating properties in the resultant container.